Continuous filament mats are widely known and are used as one component in fiber reinforced composite parts.
To make a fiber reinforced phenolic resin part having a continuous filament mat, the continuous filament mat must first be produced. Traditionally, the continuous fiber mat is produced by first introducing a sizing to the continuous glass fiber by known methods. A polyester binder system is then introduced to the sized fiber using a curtain coater or some similar technique to flood the glass fiber. The flooded sized fiber is then dried in an oven to form the continuous filament mat. The mat and a glass roving(s) are then subsequently wetted with a phenolic resin, typically by running the mat and roving through a phenolic resin bath. The wetted mat and glass roving are then introduced into a heated pultrusion die. The die shapes the mat and glass roving into a resin/glass composite that is then cured to form a pultruded part.
One problem with known methods is that the polyester binder materials used to form the continuous filament mats are not fully compatible with the phenolic resins that form the resin matrix. This affects the performance of the composite part.
It is thus highly desirable to make a binder system that is fully compatible with the phenolic resin bath, thereby forming fiber reinforced phenolic resin composite parts having potentially superior performance characteristics.